Valve-gear.



W. E. JOHNSTON.

VALVE GEAR.

APPLICATION FILED NOV.1B,1909.

1,032,367, Patented July 9,1912.

3 SHEETS SHEET 1.

WWW

W. B. JOHNSTON.

VALVE GEAR.

APPLIGATION FILED NOV. 18,1909.

Patented July'9, 1912.

3 SHEETSSHBET Z.

W. E. JOHNSTON.

VALVE GEAR.

APPLICATION FILED NOV. 18,1909.

' Patented July 9, 1912.

3 SHEETS-SHEET 3.

3 MO Z M Z. ZM Z? Z w M/ r/vzssats 1477 QF/VEYS wayennn n. Jomvs'ron, or sr. PAUL, iamnnsom.

VALVE-GEAR.

Spepificatiomcf Letters Patent.

Iatented Jnly e, 1912;

Application filed fiovember 18, 1929. Serial No. 528,819.

To alt whom it may concern;

Be it known that I, 'VVAYBURN EQ-JOHN- STON, of St. Paul, Ramsey county, Minnesota, have invented certain new and useful Improvements in Valve-Gears, of which the following is a specification.

My invention relates to valve gears for engines, particularly locomotives, and the object of the invention is to dispense with the usual link and block mechanism and ob tain ice. A further object is to reduce the cost of application of the device to an engine and the cost of maintenance, the wearing parts being easily replaced by the use of simple shop facilities.

A still further object is to provide a mechanism in which the accuracy of motionis not affectedby the vertical or lateral motion of the main wheels on a rough track, and to provide a mechanism in which the centers of the steam chests may be nearer the center the construction and arrangement of the ofthe engine in engines of certain types.

Other objects of the invention will appear from the following detailed description.

The invention consists generallyin various constructions and combinations, all as hereinafter described and particularly pointed out in the claims.

In the accompanying drawings forming part of this specification, Figure l is a side,

elevation of a portion of a locomotive, illustrating the application of my invention Fig. 2 is a diagrammatic view thereto. illustrating the gear set for forward motion, Fig. 3 is asimilar view illustrating the gear set for reverse, Fig. 4 is a detail view illustrating that portion of the mechanism which forms the subject matter of my invention, Fig. 5 is a vertical, sectional view looking toward the right on the line e -a9 of Fig. 4:, Fig. 6 is a detail, sectional viewillustrat-ing 'rocker. x

In the drawing, 2 represents the engine cylinder, 3 the steam chest and 4 a piston valve of the inside admission type.

5 represents a cross head, 6 guides therefor, 7 the valve rod and 8 the valve rod cross head. A

9 is a cross head arm and 10 a union link an increased accuracy of motion in servconnecting it with a combinatioh lever 11, which is pivoted on the valve rod cross head. v

The main rod 12connects the cross head 5 with a main crank pin 13.

14 is an eccentric, crank and 15 an eccentric rod connectingsaid crank with an oscillating lever This lever is pivoted at 17 on a slide 18' which forms the oscillating lever fulcrum, andis" back and forth on a guide 19. Areachrod 20 connects the slide 18 ,Wlt-lL'BIi arm 21 on a reversing shaft,-22 which extends across the engine for the control of the gear on the opposite side. A furt'her extension of said rod 20 leads from said shaft to the re versing lever in the cab, (not. shown.) Through this reach rod 20! the engineer may rock theshaft 22 intlieilsual way." p

23 is a rocker box having bearings for a rocker 24 thatis provided with armsi25 and 26. Links 27 connect the end of the arm 25 with the middle portioif of t heoscillating lever 16 and a transmission bar 28 connectsbthe arm 26 with the upper-endpf the combination lever 11 above its pivotal movable horizontally connection with the crosshead 8' for inside admission valves or below said pivotal connection for outside admission valves.

The movement of the parts togobtain a forward or reverse movement of the valve in back motion is illustrated in Fig. 4; If the oscillatin lever and the links 27 are set so that t links with the arm 25 and the pivot 17 are concentric, no motion will be transmitted to the transmission. bar 28, the rocker arm 26 being then stationary. If the reversing lever is thrown forward and the slide moved to the position indicated in Fig. 2, the valve will assume the position shown in said figure, taking steam in the front of the piston,

and opening the cylinder in rear of the pieton to the exhaust. In Fig. 3 the reverse position is shown with the cylinder taking steam in rear of the piston.

e5 e pivotal connection of said 1 I have-shown the combination lever 11 on the outer side of the crosshead andguides therefor, but it may be arranged on the inner side in certain types of engines, should this construction be desirable. The transmission bar 28 may bejmade of any length to suit, and the rocker 24 and oscillating lever 16 may therefore be located to make the eccentric rod 15 as long as may be desired.

The connection between the eccentric rod 15 and oscillating lever 16 in its central position may be made level with the center of the main axle. The center line of motion of-tlie eccentric rod 15 is therefore practically horizontal and is perpendicular to the vertical motionof the main axle. This I consider an important feature of my invention', as this construction prevents inaccuracies in the valve motion due to vertical motion of the main wheel in passing over rough track.

It will be noted that the valve gear mech anism is all arranged on the outside of the engine, where it is open for inspection and easily reached at any time.

I have shown the gear as arranged for an inside admission valve of the piston type, but the gear is eqnallywell suited for an outside admission valve of either the slide 'or piston types. For outside admission valves, the transmission bar 28 will be connected to thecombination lever 11 below the valve rod crosshead connection, and the eccentric crank 14; will be turned on the crank pin 13 so as to give the eccentric rod 15 a motion the reverse of that which it would receive frtim the arrangement as shown on the drawings herewith.

I have shown the valve stem 7 connected to a crcsshead 8, which slides on a horizontal guide, but this arrangement may be modified as required, provided that-the operative relations between the transmission bar 28, combination lever 11 and the valve stem 7 are not altered.

1 I have shown two backwardlyi'extendingarms 25 on' the rocker 24, but one such arm m'ay' -be used working-inside of the oscillating" lever. The lever 16 in this case would have trunnions at 17 on its outer sides and a double guide 19 having a bar on each side of the oscillating lever:

I claim as my invention? 1. A-valve gear comprising a slide, a-horizontal: guide therefor, a reach rod pivotally c'onnected'with said slide, a lever pivoted atone end on said slide, an eccentric rod pivotally connected with the other end of said lever, a rocker having arms 25 and 26 thereon, links pivotally connecting said [arms 25 with the middle portion of said le-' ver, said links being one-half the length substantially of said lever, avalve, a cylin der cross head, and mechanism connecting the said arm 26 .with said valve and cross head.

2. A valve gear comprising a slide, a guide therefor and an operating means connected therewith, an oscillating lever pivoted at one end on said slide, an eccentric rod pivotally connected with the other end of said lever, a rocker having an arm thereon, a link pivotally connecting said arm I with said oscillating lever, the connection of the parts balancing the-strain, the movement of the pivotal connectionof the oscillating lever with the slide correcting for the angularity of the'eccentric rod, a valve, a cylinder cross head, and mechanism operatively connecting said rocker with said valve and cross head.- i

3. A valve gear comprising a slide, a

guide therefor, and an operating means con nected with said slide, an oscillating lever having one end pivotally connected with said slide, an eccentric rod pivotally connected with'the other end of said oscillating the ends thereof, the pivotal connection of said links with said arm and the pivot of said lever on said slide being concentric substantially'wlien said slide is in its neuzlever, a rocker having an arm thereon, links pivotally connect ng said arm with said oscillating lever at a point intermediate to tral position, the arrangement of said lever,

links, and eccentric rod balancing the strain and eliminating lateral pressure on the pivots, a valve, a cylinder cross head, and

mechanism operativelyi. connecting said 4 rocker with said valve and cross head.

4. A valve gear comprising a slide, a

.guide therefor, a reversing shafthaving an armthereon and means for rocking said arm, a reach rod connecting said slide with;

said arm, a' lever pivoted at one'end on said slide, an eccentric rod pivotally connected with the other end. of said lever, a rocker having arms thereon, links pivotally connecting oneiof said arms with saidlever, a valve, a cylinder cross head, and mechanism" connecting another of said rocker arms with said valve andcross head.

- In witness whereof, I have hereunto set my hand this 13th day of November 1909.

. WAYB'URN E. J OHNSTON.

Witnesses: '1' i J. FRANK HORN, W; T. FRANCIS.

Washington, I). 0.?

Copies 01 this patent may be obtained for five cents each, by addressing the Commissioner of Patents, 

